Feature #3: Server SKU support for Enrolment

The Disco Client (which is launched by the Bootstrapper) supports
Windows Server SKUs. Removes dependancy on WLANAPI.DLL. Updates to
enrolment allows for successful addition to System Critial objects (eg.
DC/PDCs) into Disco without making any changes to AD objects.

Disco.BI/BI/Extensions/DeviceActionExtensions.cs

@@ -93,7 +93,7 @@ namespace Disco.BI.Extensions
             if (d.ComputerName != null)
             {
                 var adAccount = d.ActiveDirectoryAccount();
-                if (adAccount != null)
+                if (adAccount != null && !adAccount.IsCriticalSystemObject)
                 {
                     adAccount.DisableAccount();
                 }
@@ -120,7 +120,7 @@ namespace Disco.BI.Extensions
             if (d.ComputerName != null)
             {
                 var adAccount = d.ActiveDirectoryAccount();
-                if (adAccount != null)
+                if (adAccount != null && !adAccount.IsCriticalSystemObject)
                 {
                     adAccount.EnableAccount();
                 }